Latch mechanism for a closure member

ABSTRACT

A latch mechanism for a closure member that has a leaf spring that cooperates with a main bolt and an auxiliary bolt to maintain the bolts in a normally extended position. The two bolts are retractable together against the bias of the leaf spring and the latter serves to provide an increased extension of the main bolt when the latter is released and the auxiliary bolt is maintained in the retracted position.

United States Patent 11 1 1111 3,907,347 Hollis Sept. 23, 1975 [5 LATCH MECHANISM FOR A CLOSURE 3353.858 11/1967 Neary 292/169.l3 x MEMBER 3.586.361 6/1971 Ohno 70/143 X 3.666.306 5/1972 Genakis 70/143 X [75] Inventor: Lyn C. Hollis, Pontiac, Mich. [73] Assignee: General Motors Corporation, Primary Examiner-Robert L. Wolfe Detroit, Mich. Attorney, Agent. or FirmEdward J. Biskup [22] Filed: Nov. 21, 1974 w 211 Appl. No; 525,997 [57] ABSTRACT A latch mechanism for a closure member that has a leaf spring that cooperates with a main bolt and an 7 auxiliary bolt to maintain the bolts in a normally ex- [58] Fie'ld 292/169 13 169 19 tended position. The two bolts are retractable together ar 292/42 against the bias of the leaf spring and the latter serves to provide an increased extension of the main bolt when the latter is released and the auxiliary bolt is [56] g gzg g gif maintained in the retracted position. 1.220.939 3/1917 Bock 70/143 3 Claims 7 Drawing Figures US Patent Sept. 23,1975 3,907,347

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LATCH MECHANISM FOR A CLOSURE MEMBER This invention concerns a door latch and more particularly a latch mechanism for use with doors that are relatively thin, narrow and light in weight and that require a minimum amount of force to cause the door to be moved to a closed position.

In the preferred form, the latching mechanism according to the invention is adapted to be mounted on a door that is supported for movement between an open position wherein the door is spaced from a fixed strike plate and a closed position wherein the door is located adjacent the strike plate. The latching mechanism includes a housing which slidably supports a main bolt and an auxiliary bolt with the main bolt being adapted to assume three positions; namely, a retracted position wherein the outer end of the bolt is located substantially at the outer edge of the housing, a normally extended position wherein the outer end of the bolt is located outwardly beyond the edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond the edge of the housing a distance greater than the predetermined distance. The auxiliary bolt is adapted to assume two positions; namely, a normally extended position wherein the outer end of the auxiliary bolt extends out of the housing a distance substantially equal to the aforementioned predetermined distance, and a retracted position wherein the outer end of the auxiliary bolt is positioned substantially at the edge of the housing. The housing also includes a leaf spring which, when in a free-form state, cooperates with the inner ends of the main bolt and the auxiliary bolt for maintaining both bolts in the normally extended positions when the door is in the open position. The leaf spring is adapted to be bent into a sinuous form during the closing movement of the door and causes the main bolt to be moved to the fully extended position into the opening in the strike plate when the door is in the closed position and the auxiliary bolt is maintained in the retracted position.

The objects of the present invention are to provide an improved latch mechanism for a closure member that has a bolt which normally extends out of a housing a predetermined distance when the closure member is in an open position and that is moved by a leaf spring outwardly out of the housing a distance greater than said predetermined distance when the closure member is in the closed position; to provide an improved latch mechanism for a closure member that has a main bolt and an auxiliary bolt that normally extend out of a housing a predetermined distance and in which both bolts are movable into the housing against the bias of a leaf spring which stores energy that is subsequently used to extend the main bolt into a strike plate a distance greater than the predetermined distance; and to provide an improved latch mechanism that has a main bolt and an auxiliary bolt that cooperate to bend a leaf spring into a sinuous form when retracted together into the latch housing and in which the leaf spring causes the main bolt to have an amplified displacement outwardly from the housing when the auxiliary bolt maintains the retracted position and the main bolt is free to move outwardly.

Other objects and advantages of the present invention will be more apparent from the following detailed description when taken with the drawings in which:

FIG. 1 is a sectional view showing the latch mechanism according to the invention mounted within a door that is positioned in an open position relative to a fixed strike plate;

FIG. 2 is a view taken on lines 22 of FIG. 1',

FIG. 3 is a view similar to FIG. 1 but shows the door in a partially closed position with the main bolt and the auxiliary bolt of the latch mechanism located in the retracted position;

FIG. 4 is a view taken on lines 4-4 of FIG. 3;

FIG. 5 is a view similar to FIG. 1 but shows the door in the fully closed position with the auxiliary bolt in the retracted position and the main bolt located in the fully extended position;

FIG. 6 is a view taken on line 6-6 of FIG. 5; and

FIG. 7 is an enlarged view taken on line 7-7 of FIG. 2 showing the connection between the central portion of a leaf spring and the main bolt.

Referring to the drawings and more particular FIGS. 1 and 2 thereof, a cross-sectional view of a hinged vertically oriented door or closure member 10 is shown with the door 10 assuming an open position relative to a door frame 12 and incorporating a latch mechanism 14 made in accordance with the invention. The door frame 12 has a strike plate 16 fixed thereto that is formed with a stop 18 for the door 10, an elongated vertical opening 20 for a bolt, and the usual camming surface 22. As is conventional, a cavity 24 for accommodating the bolt is formed in the door frame 12 and registers with the opening 20 formed in the strike plate.

The latch mechanism 14 comprises a main bolt 26, an auxiliary bolt 28, and a leaf spring 30 which, as seen in FIGS. 2 and 7 has the central portion thereof connected by a clip 32 to the inner end of the main bolt 26. All of the aforementioned elements together with two pairs of spring support pins 33, 34 and 35, 36 are located within a housing comprising parallel side walls 42 and 44, an end wall 46, and upper and lower walls 48 and 50.

The auxiliary bolt 28 is supported in the housing for sliding movement and is generally U-shaped in cross section consisting of a vertical base plate 52 with integrally formed legs 54 and 56. A horizontal plane passing through the longitudinal central axis of either of the legs 54 or 56 would be perpendicular to the plane of the base plate 52. The outer end of each of the legs 54 and 56 and of the base plate 52 terminates with a curved outer surface 58. The inner end of the base plate 52 is formed with a concave surface 59 while the inner end of each leg 54, 56 is formed with a planar surface 60 that normally engages one end of the leaf spring 30 and is located in a vertical plane which is perpendicular to the plane of the base plate. As seen in FIG. 2, each leg 54, 56 has a slot 61 formed therein which receives a pin 62 attached to wall 44 for limiting movement of the auxiliary bolt inwardly and outwardly relative to the housing. Although not apparent from the drawings, it will be noted that each of the legs 54 and 56 of the auxiliary bolt 28 is of a width substantially equal to the transverse distance between the side walls 42 and 44 as seen in FIG. 1.

As seen in FIG. 2, the main bolt 26 is generally square in configuration and is located within the confines of the legs 54 and 56 and the base plate 52 of the auxiliary bolt 28. The main bolt 26 has the outer end thereof formed with a curved surface 63 which merges with and has the same configuration as the surface 58 of the auxiliary bolt 26. A rod 64 is fixed to the main bolt 26 and extends outwardly through horizontally elongated and identical slots 65 and 66 formed respectively within the housing and in the door 10. The rod 64 serves as a handle which permits the main bolt 26 to be slidably moved into a retracted position in a manner which will hereinafter be described. A pin 67 fixed with the main bolt 26 is received within a slot 68 formed in the base plate 52 so that the main bolt 26 and the auxiliary bolt 28 move inwardly together.

Thus, from the above description, it should be apparent that both the auxiliary bolt 28 and the main bolt 26 are slidably supported within the housing with the main bolt 26 being located along side the auxiliary bolt 28 and being movable relative to the auxiliary bolt in an outward direction or to the left as seen in FIG. 2. On the other hand, when the main bolt 26 is moved in an inward direction or towards the right as seen in FIG. 1, the pin 67 of the main bolt engages the right side of the slot 68 causing the auxiliary bolt 28 and the main bolt to cause both bolts to move together against the bias of spring 30.

The operation of the latch mechanism 14 described above is as follows:

As seen in FIGS. 1 and 2, both the main and auxiliary bolts 26 and 28 are located in a normally extended position when the closure member is in the open posi tion. At such time, the leaf spring 30 is in the free-form or relaxed state and serves to locate the outer ends of the bolts 26 and 28 outwardly a predetermined distance relative to the outer edge of the housing as limited by the engagement of the pin 62 with the right side of the slot 61 and as provided by the connection between the clip 32 and the central inner end of the main bolt. When the door 10 is partially closed as seen in FIG. 3, the main and auxiliary bolts 26 and 28 are cammed into a retracted position by strike plate 16 and cause the inner end of each bolt to bend the leaf spring 30 into a sinuous form as seen in FIG. 4. Subsequently, the closure member 10 moves into the fully closed position as limited by the stop 18 of the strike plate 16 shown in FIG. 5. The auxiliary bolt 28, at such time, maintains contact with the strike plate 16 and therefore remains in the retracted position because the opening 20 is sized to only receive the main bolt. The main bolt 26, however, being axially aligned with the opening 20 in the strike plate 16 then moves outwardly into the opening 20 a distance greater than the aforementioned predetermined distance maintained by the main bolt when the door 10 is in the open position. This occurs because the outer ends of the leaf spring are bent inwardly by the inner ends of the legs and, as a result, cause the central portion of the spring 30 to bow out wardly and apply an outward force on the main bolt 26 to move the latter towards the left beyond the normally extended position of FIG. 2. In this manner, the leaf spring 30 extends the bolt 26 to the fully extended position of FIGS. 5 and 6 as limited by the connection provided by the pin 67 and slot 68.

Thus, from the above description it should be apparent that when both the auxiliary and main bolts 26 and 28 are moved into the housing 50, the leaf spring 30 is flexed into the shape shown in FIG. 4, and subsequently dissipates a portion of the stored energy by acting through the center portion of the spring 30 to move the main bolt 26 outwardly relative to the housing 40. The increased displacement of the main bolt 28 results in a more positive lock without requiring higher closing forces for the door. Also, and as should be apparent, after the door 10 is closed, the bolt 26 can be retracted out of the opening 20 in the strike plate 16 by moving the rod 64 manually to the right, as shown in FIG. 4, followed by movement of the door to the position of FIG. 1. After the rod 64 is released and the door 10 is opened, the various elements of the latch mechanism 14 will again assume the normally extended positions of FIGS. 1 and 2.

Various changes and modifications can be made in this construction without departing from the spirit of the invention. Such changes and modifications are contemplated by the inventor and he does not wish to be limited except by the scope of the appended claims.

I claim:

1. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is located substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond said outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond said outer edge a distance greater than said predetermined distance. an auxiliary bolt slidably supported in said housing adjacent said main bolt and having an outer end adapted to assume a normally extended position wherein the outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein the outer end of the auxiliary bolt is located substantially at the outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, and a leaf spring carried by said main bolt and having portions engaging said auxiliary bolt for maintaining the main bolt and the auxiliary bolt in said normally extended positions when said closure member is in said open position and for causing the main bolt to be moved to said fully extended position into the opening in said strike plate when said closure member is in said closed position.

2. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is located substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond said outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond said outer edge a distance greater than said predetermined distance, an auxiliary bolt slidably supported in said housing and having an outer end adapted to assume a normally extended position wherein said outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein said outer end of the auxiliary bolt is located substantially at said outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, a leaf spring having a central portion and opposed end portions, means connecting the central portion of the leaf spring to the main bolt, means carried by said housing for supporting the leaf spring adjacent said opposed end portions whereby the opposed end portions continuously contact the auxiliary bolt and serve to maintain the main bolt and the auxiliary bolt in said normally extended positions when said closure member is in said open position and cause the main bolt to be moved by the central portion of the leaf spring to said fully extended position into the opening in said strike plate when said closure member is in said closed position.

3. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is positioned substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond the outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond the outer edge a distance greater than said predetermined distance, an auxiliary bolt having a pair of legs formed therewith and being slidably supported in said housing along side said main bolt with said pair of legs straddling the main bolt, said auxiliary bolt having an outer end adapted to assume a normally extended position wherein said outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein said outer end of the auxiliary bolt is located substantially at said outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, a leaf spring having a central portion and opposed end portions, means connecting the central portion of the leaf spring to the main bolt, means rigidly formed with said housing for restraining movement of the leaf spring at points adjacent said opposed end portions whereby the opposed end portions continuously contact the legs of the auxiliary bolt and serve to maintain the main bolt and the auxiliary bolt in said normally extended position when said closure member is in said open position and cause the main bolt to be extended by the central portion of the leaf spring to said fully extended position into the opening in said strike plate when said closure member is in said closed position, said leaf spring adapted to assume a free-form state and be located in a transverse plane when the main bolt and the auxiliary bolt are in the normally extended position and assume a sinuous form when said main bolt and auxiliary bolt are in the retracted position. 

1. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is located substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond said outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond said outer edge a distance greater than said predetermined distance, an auxiliary bolt slidably supported in said housing adjacent said main bolt and having an outer end adapted to assume a normally extended position wherein the outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein the outer end of the auxiliary bolt is located substantially at the outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, and a leaf spring carried by said main bolt and having portions engaging said auxiliary bolt for maintaining the main bolt and the auxiliary bolt in said normally extended positions when said closure member is in said open position and for causing the main bolt to be moved to said fully extended position into the opening in said strike plate when said closure member is in said closed position.
 2. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is located substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond said outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond said outer edge a distance greater than said predetermined distance, an auxiliary bolt slidably supported in said housing and having an outer end adapted to assume a normally extended position wherein said outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein said outer end of the auxiliary bolt is located substantially at said outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, a leaf spring having a central portion and opposed end portions, means connecting the central portion of the leaf spring to the main bolt, means carried by said housing for supporting the leaf spring adjacent said opposed end portions whereby the opposed end portions continuously contact the auxiliary bolt and serve to maintain the main bolt and the auxiliary bolt in said normally extended positions when said closure member is in said open position and cause the main bolt to be moved by the Central portion of the leaf spring to said fully extended position into the opening in said strike plate when said closure member is in said closed position.
 3. A latch mechanism for a closure member that is supported for movement between an open position wherein said closure member is spaced from a fixed strike plate having an opening formed therein and a closed position wherein said closure member is located adjacent said strike plate, said latch mechanism comprising a housing having an outer edge, a main bolt slidably supported in said housing, said main bolt having an outer end and an inner end and being adapted to be located in a retracted position wherein the outer end of the bolt is positioned substantially at the outer edge of the housing, a normally extended position wherein the outer end of said main bolt is located outwardly beyond the outer edge of the housing a predetermined distance, and a fully extended position wherein the outer end of the bolt is located outwardly beyond the outer edge a distance greater than said predetermined distance, an auxiliary bolt having a pair of legs formed therewith and being slidably supported in said housing along side said main bolt with said pair of legs straddling the main bolt, said auxiliary bolt having an outer end adapted to assume a normally extended position wherein said outer end of the auxiliary bolt extends out of said housing a distance substantially equal to said predetermined distance and a retracted position wherein said outer end of the auxiliary bolt is located substantially at said outer edge of said housing, said outer end of the auxiliary bolt adapted to contact said strike plate and be moved into and be maintained in its retracted position when said closure member is in said closed position, a leaf spring having a central portion and opposed end portions, means connecting the central portion of the leaf spring to the main bolt, means rigidly formed with said housing for restraining movement of the leaf spring at points adjacent said opposed end portions whereby the opposed end portions continuously contact the legs of the auxiliary bolt and serve to maintain the main bolt and the auxiliary bolt in said normally extended position when said closure member is in said open position and cause the main bolt to be extended by the central portion of the leaf spring to said fully extended position into the opening in said strike plate when said closure member is in said closed position, said leaf spring adapted to assume a free-form state and be located in a transverse plane when the main bolt and the auxiliary bolt are in the normally extended position and assume a sinuous form when said main bolt and auxiliary bolt are in the retracted position. 